function nthUglyNumber(n) {
  let a = 0, b = 0, c = 0, dp = new Array(n)
  dp[0] = 1
  for (let i = 1; i < n; i++) {
    let n2 = dp[a] * 2, n3 = dp[b] * 3, n5 = dp[c] * 5
    dp[i] = Math.min(n2, n3, n5)
    if (dp[i] === n2) {
      a++
    }
    if (dp[i] === n3) {
      b++
    }
    if (dp[i] === n5) {
      c++
    }
  }
  return dp[n - 1]
}